Assessment of the Implementation of Energy Conservation Opportunities Arising from Energy Audits;A Study of Four-Star and Five-Star Hotels in Nairobi Kenya

This study assesses the implementation of energy conservation opportunities in four-star and five-star hotels in Nairobi. The Covid-19 pandemic had a significant impact on the Hospitality Industry. Currently, there is a growing inclination to furnish guests with superior and sustainable services in an energy-efficient and eco-friendly way. Comprehensive research was conducted from energy audits gathered from the establishments and contracted auditing companies, on top of this, hotel staff were given digital questionnaires. To add to the data, the researcher surveyed the hotels with engineering managers. The Energy Audits found that all 10 hotels had adopted Energy Conservation Opportunities (ECOs). After further analysis, the mean adoption rate of Energy Conservation Opportunities (ECOs) during the past three years was 55.83%, which was below the aim of 100%. According to studies, hotel staff manages energy to cut costs. The researcher found that hotels use up a lot of energy. However, they have conservation potential, depending on government policies, costs, ease of implementation, and management commitment to sustainable practices. Essentially, Energy Conservation Opportunities (ECOs) reduce energy expenditures and boost reliable revenues, especially during high energy prices and uncertainty.

Using Artificial Neural Networks for Energy Regulation Based Variable-speed Electrohydraulic Drive

In the energy regulation based varibable-speed electrohydraulic drive system, the supply energy and the demanded energy, which will affect the control performance greatly, are crucial. However, they are hard to be obtained via conventional methods for some reasons. This paper tries to a new route： the definitive numerical values of the supply energy and the demanded energy are not required, except for their relationship which is called energy state. A three-layer back propagation（BP） neural network was built up to act as an energy analysis unit to deduce the energy state. The neural network has three inputs： the reference displacement, the actual displacement of cylinder rod and the system flowrate supply. The output of the neural network is energy state. A Chebyshev type II filter was designed to calculate the cylinder speed for the estimation of system flowrate supply. The training and testing samples of neural network were collected by the system accurate simulation model. After off-line training, the neural network was tested by the testing data. And the testing result demonstrates that the designed neural network was successful. Then, the neural network acts as the energy analysis unit in real-time experiments of cylinder position control, where it works efficiently under square-wave and sine-wave reference displacement. The experimental results validate its feasibility and adaptability. Only a position sensor and some pressure sensors, which are cheap and have quick dynamic response, are necessary for the system control. And the neural network plays the role of identifying the energy state.

An adaptive energy regulation in a memristive map linearized from a circuit with two memristive channels

Nonlinear circuits can show multistability when a magnetic flux-dependent memristor(MFDM) or a charge-sensitive memristor(CSM) is incorporated into a one branch circuit,which helps estimate magnetic or electric field effects.In this paper,two different kinds of memristors are incorporated into two branch circuits composed of a capacitor and a nonlinear resistor,thus a memristive circuit with double memristive channels is designed.The circuit equations are presented,and the dynamics in this oscillator with two memristive terms are discussed.Then,the memristive oscillator is converted into a memristive map by applying linear transformation on the sampled time series for the memristive oscillator.The Hamilton energy function for the memristive oscillator is obtained by using the Helmholtz theorem,and it can be mapped from the field energy of the memristive circuit.An energy function for the dual memristive map is suggested by imposing suitable weights on the discrete energy function.The dynamical behaviors of the new memristive map are investigated,and an adaptive law is proposed to regulate the firing mode in the memristive map.This work will provide a theoretical basis and experimental guidance for oscillator-to-map transformation and discrete map energy calculation.

Realizing high-performance organic solar cells through precise control of HOMO driving force based on ternary alloy strategy

A good deal of studies have proven that effective exciton dissociation and fast hole transport can operate efficiently in non-fullerene organic photovoltaics(OPVs)despite nearly zero driving force.Even so,whether such a phenomenon is universal and how small the driving force can realize the best photovoltaic performance still require a thorough understanding.Herein,despite the zero driving force based on PM6:F8IC system,a maximum short-circuit current(J_(sc))of 23.0 mA/cm^(2) and high power conversion efficiency(PCE)of 12.2%can still be achieved.Due to the continuously adjustable energy levels can be realized in organic semiconducting alloys including F8IC:IT-4F and F8IC:Y6,the suitable third components can play the role of energy level regulator.Therefore,the HOMO energy level offset(DEHOMO(D A))from zero to 0.07 and 0.06 eV is accomplished in the optimized IT-4F and Y6 ternary devices.Consequently,both ternary devices achieved substantially increased PCE of 13.8%and Jsc of 24.4 and 25.2 mA/cm^(2),respectively.Besides,pseudo-planar heterojunction(PPHJ)devices based on alloyed acceptors through sequential spin-coating method further improve the photovoltaic performance.Our work puts forward the concept of energy level regulator and prove that the ternary alloy strategy has unique advantages and huge research potential in continuously adjusting the driving force.

Regulation characteristics of oxide generation and formaldehyde removal by using volume DBD reactor

Discharge plasmas in air can be accompanied by ultraviolet（UV） radiation and electron impact,which can produce large numbers of reactive species such as hydroxyl radical（OH·）,oxygen radical（O·）,ozone（O3）,and nitrogen oxides（NOx）,etc.The composition and dosage of reactive species usually play an important role in the case of volatile organic compounds（VOCs） treatment with the discharge plasmas.In this paper,we propose a volume discharge setup used to purify formaldehyde in air,which is configured by a plate-to-plate dielectric barrier discharge（DBD） channel and excited by an AC high voltage source.The results show that the relative spectral-intensity from DBD cell without formaldehyde is stronger than the case with formaldehyde.The energy efficiency ratios（EERs） of both oxides yield and formaldehyde removal can be regulated by the gas flow velocity in DBD channel,and the most desirable processing effect is the gas flow velocity within the range from2.50 to 3.33 m s^-1.Moreover,the EERs of both the generated dosages of oxides（O3 and NO2） and the amount of removed formaldehyde can also be regulated by both of the applied voltage and power density loaded on the DBD cell.Additionally,the EERs of both oxides generation and formaldehyde removal present as a function of normal distribution with increasing the applied power density,and the peak of the function is appeared in the range from 273.5 to 400.0 W l-1.This work clearly demonstrates the regulation characteristic of both the formaldehyde removal and oxides yield by using volume DBD,and it is helpful in the applications of VOCs removal by using discharge plasma.

The Quasi-Parabolic Regulation of the Standard Free Energies of Formation of Binary Intermediate Compounds

In this paper it has theoretically proved that the relationship of the molar atomic standard free energies of formation of binary intermediate compounds to the molar fraction of component is a quasi-parabola which is called a quasi-parabolic regula- tion.

Unveiling the surface-interface properties of perovskite crystals and pivotal regulation strategies

Metal-halide perovskite solar cells have garnered significant research attention in the last decade due to their exceptional photovoltaic performance and potential for commercialization.Despite achieving remarkable power conversion efficiency of up to 26.1%,a substantial discrepancy persists when compared to the theoretical Shockley-Queisser(SQ)limit.One of the most serious challenges facing perovskite solar cells is the energy loss incurred during photovoltaic conversion,which affects the SQ limits and stability of the device.More significant than the energy loss occurring in the bulk phase of the perovskite is the energy loss occurring at the surface-interface.Here,we provide a systematic overview of the physical and chemical properties of the surface-interface.Firstly,we delve into the underlying mechanism causing the energy deficit and structural degradation at the surface-interface,aiming to enhance the understanding of carrier transport processes and structural chemical reactivity.Furthermore,we systematically summarized the primary modulating pathways,including surface reconstruction,dimensional construction,and electric-field regulation.Finally,we propose directions for future research to advance the efficiency of perovskite solar cells towards the radiative limit and their widespread commercial application.

Ultralight and hyperelastic SiC nanofiber aerogel spring for personal thermal energy regulation

Multifunctionalization is the development direction of personal thermal energy regulation equipment in the future.However,it is still a huge challenge to effectively integrate multiple functionalities into one material.In this study,a simple thermochemical process was used to prepare a multifunctional SiC nanofiber aerogel spring(SiC NFAS),which exhibited ultralow density(9 mg/cm3),ultralow thermal conductivity(0.029 W/(m·K)at 20℃),excellent ablation and oxidation resistance,and a stable three-dimensional(3D)structure that composed of a large number of interlacing 3C-SiC nanofibers with diameters of 300–500 nm and lengths in tens to hundreds of microns.Furthermore,the as-prepared SiC NFAS displayed excellent mechanical properties,with a permanent deformation of only 1.3%at 20℃after 1000 cycles.Remarkably,the SiC NFAS exhibited robust hyperelasticity and cyclic fatigue resistance at both low(~-196℃)and high(~700℃)temperatures.Due to its exceptional thermal insulation performance,the SiC NFAS can be used for personal thermal energy regulation.The results of the study conclusively show that the SiC NFAS is a multifunctional material and has potential insulation applications in both low-and high-temperature environments.

Energy band engineering via“Bite”defect located on N=8 armchair graphene nanoribbons

Graphene nanoribbons(GNRs)not only share many superlative properties of graphene but also display an exceptional degree of tunability of their electronic properties.The bandgaps of GNRs depend greatly on their widths,edges,etc.Herein,we report the synthesis path and the physical properties of atomic accuracy staggered narrow N=8 armchair graphene nanoribbons(sn-8AGNR)with alternating"Bite"defects on the opposite side.The intermediate structures in the surface physicochemical reactions from the precursors to the sn-8AGNR are characterized by scanning tunneling microscopy.The electronic properties of the sn-8AGNR are characterized by scanning tunneling spectroscopies and 6//6V mappings.Compared with the perfect N=8 armchair graphene nanoribbons(8AGNR),the sn-8AGNR has a larger bandgap,indicating that the liB\Xen edges can effectively regulate the electronic structures of GNRs.

THE PIGMENT-PROTEIN COMPLEXES OF HIGHER PLANTS MIGRATION IN THYLAKOID AND THE REGULATION OF LIGHT ENERGY DISTRIBUTION BETWEEN PHOTOSYSTEMS

Appressed and non-appressed lamella membranes of Castor bean leaf chloroplasts were separated by non-ionic detergent Triton-X 100.Appressed membranes showed a high oxygen-evolving activity and low chl a/b ratio. Examining with SDS-PTGE and liquid nitrogen temperature fluorescence measurement showed that they contained only PSII and light-harvesting pigment-protein complexes （LHCP）,and there was no detectable amount of PSI. Freeze-fracture electromicroscopic observation confirmed that this part was really an appressed lamella membrane. Through divalent cation Mg++, the thylakoid membranes were induced to unstack and restack.With the addition of Mg++, the fluorescence intensity was changed instantly. We realized that there existed two processes:One was a rapid process which was accomplished within 30 s. The other was a slow process of which the time duration was about 60 min. This dual effects of Mg++ had not been reported before.We had analyzed the change of F685/F730 and discussed the

A SiC nanowires/Ba_(0.75)Sr_(0.25)Al_(2)Si_(2)O_(8) ceramic heterojunction for stable electromagnetic absorption under variable-temperature

The application of semiconductor materials was limited as electromagnetic absorption materials,due to the unstable absorption performance caused by the temperature sensitivity.In this work,a structurally controllable ceramic heterojunction was developed by assembling structural units of SiC nanowires(SiCnws)and Ba_(0.75)Sr_(0.25)Al_(2)Si_(2)O_(8)(BSAS).Benefiting from the optimization of the energy gap and the construction of heterogeneous interfaces,the ceramic heterojunction can achieve stable electromagnetic absorption from room temperature to 600℃,the effective absorption bandwidth is almost unchanged.And the minimum reflection loss value reached-63.6 dB at 600℃.Meanwhile,the SiCnws/BSAS ceramic heterojunction shows stable electromagnetic absorption performance in various simulated outdoor environments,including acid rain,seawater,high temperature and water vapor corrosion.This result provides a fire-new idea to realize the environmental adaptability of electromagnetic absorption materials and largely broadens its application prospect.